An introduction to the most essential lens filters for your kit bag - that will make a huge difference to your images

Beginner

I'm a firm believer that great images don't require the most advanced and expensive equipment. It's a cliché saying, but it's the photographer behind the camera that matters. You can capture great images on any device.

However, there are specific tools that can help you. Filters are one of them. They won't instantly make you a better photographer, but understanding how and when to use them will make it possible to achieve techniques you otherwise wouldn't.

Filters are something that most landscape photographers rely on in their work. There are simply so many advantages of having them available.

But where do you begin? A quick search on 'filters for photography' reveals that there's an abundance of options available. There are different types of filters, different systems and different prices.

What are filters?


Before we get into the specifics, you might be wondering what filters are and why they can improve your photography.

Filters come in various shapes and purposes, but, in general, they are placed in front of your lens to achieve a specific look or technique. Some filters affect the contrast and colors, and others require you to use a slower shutter speed. Some darken areas of the photo while others just protect the lens.

What they all have in common is that they can make or break a photo. Certain filters can give excellent results, but they require a little extra understanding from you. Just placing a filter in front of the lens won't instantly make an image great.

Let's take a closer look at the most popular filters for photography:

UV Filters


A UV filter is a transparent filter which blocks ultraviolet rays. However they have little to no effect on the photo itself and mainly work as a protective barrier for the lens. They are usually cheap - $10 is a small investment to protect a $2000 lens, should you have an accident.

UV filters are a fairly popular filter amongst beginner photographers, but it's one that few professional photographers would consider 'essential'.

UV filters block out ultraviolet rays. However, they generally they have very little effect on the quality of the photo itself and are mainly used as a protective barrier for the lens. Image by Callum Sebastian Warwick.

Polarization Filters


The second most common filter, to begin with, is a Polarizer. This filter comes in two main options: a standard Polarizer (PL) and a Circular Polarizer (CPL).

Both versions work similarly, but the CPL is a more flexible option that most photographers prefer and is the option I recommend.

So, what is a Polarizer?

A polarizer is a filter that serves more than one purpose and can instantly make a difference in your photo. The main advantages are:



The CPL makes it possible to rotate the polarization and better target the specific areas needed (for example, to neutralize shiny foreground rocks).

Take a look at this example to see what a PL or CPL filter can do:

Left: image without a CPL filter. Right: image with CPL applied. Notice the improved contrast and saturation?

Neutral Density Filters


Neutral Density Filters, or ND Filters, are arguably the most popular filters amongst landscape photographers. These darkened filters restrict the amount of light letting through the lens, forcing you to use a slower shutter speed.

By doing so, you're able to blur or obscure any moving elements within the frame. An ND filter is how you create those images where the water looks like silk or clouds dragged across the sky. Such as this:

Captured with the use of an ND filter and a slow shutter speed to obscure the moving water, making it silky-smooth.
The same image without the ND filter applied.

Neutral Density Filters come in a variety of options. I'll discuss the specific filter systems in a bit, but you need to know that ND Filters come in different strengths for now. What this means is that some filters are darker than others.

The degrees of darkening are typically referred to as 3-Stop, 6-Stop or 10-Stop (though higher and lower values are available).

Why is this important?

Because the darker the filter is, the less light reaches the sensor in the same amount of time. A dark filter might require a 1000-times longer shutter speed! That's how you can achieve long exposures of several minutes.

Top tip:

It's essential to keep in mind that you need to mount the camera on a tripod when working with slow shutter speeds. Failing to do so will result in blurry images!


Graduated Neutral Density Filters


A Graduated Neutral Density Filter, or a GND, is similar to a regular ND Filter. But there's one difference: only the top part of the filter is darkened while the rest remains transparent.

The transition between the darkened and transparent part is either softmedium or hard. This describes how long the transition area is in the filter. Personally, I prefer medium transitions.

But what is a GND filter, and why would you want a filter that's only partly darkened? I'll let this photo explain:

Left: image with the GND filter applied Right: image without the GND filter. Applying a GND filter to the scene has created a much more balanced exposure.

I'm sure you've captured more than one image where the sky is perfect, but the landscape is completely black, or the landscape is perfect, and the sky is completely white. Fixing this is the main purpose of a Graduated Neutral Density Filter.

The filter is used to darken the bright sky and create a well-balanced exposure where both the sky and landscape looks good.

This is a tool that many photographers rely on, but it's worth mentioning that it's not always the best choice. It's perfect for photographing scenes with a relatively straight horizon, but it's not ideal when, for example, photographing mountains. In those cases, I recommend instead, capturing multiple images of different exposures to blend together or using gradients in post-production to balance the exposure. 

Filter Systems 


There are more filters than those mentioned above, but these are the only ones you need to be aware of. Besides the UV Filters, all of these are an essential part of my backpack, and I believe they will do wonders for your photography too.

But there are still a few more things you need to know about filters; not only are there different types of filters, but there are also different filter systems.

There are two main systems to work with, and they both have their pros and cons. There's not necessarily one that's better than the other, and which one you should choose will depend on your photography.

Let's take a closer look at the options:

Screw-On / Circular Filters


Screw-on or circular filters are the most common, especially amongst beginning photographers. The cheapest options are a lot cheaper than the other systems, making this a great place to begin.

The filters are screwed directly onto the front element of your lens. This comes with a few advantages and disadvantages:

A screw-on filter placed in front of the camera lens on a DSLR camera.

This is a good system, to begin with, as there are very affordable options (down to $15-20 per filter) but keep in mind that the cheapest filters aren't always the best. There are also options that cost $150 or $200+, but that's not to say that they are better than the ones in the middle of that price range.

Square / Drop-In Filters


This is a slightly more advanced filter system that's loved by landscape photographers for its flexibility. It works in a similar way as the screw-on filters, but instead of mounting the filter to the lens, you first mount a filter holder. The filter holder is screwed onto the front of the lens and typically has three slots where you can slide in filters.

A drop-in ND filter placed in front of the lens with a filter mount.

What this means is that you can use multiple filters at once.. This is an important factor and something you'll grow to love when you become more comfortable with using filters.

As with the screw-on filters, there are a few advantages and disadvantages: 



Due to their size and weight, square filters aren't ideal for those long hiking trips where every gram you're carrying matters. But for anything else, this is the filter system I'd go for, at least if you've got some experience with filters.

It's a more flexible system, and being able to use multiple filters at once is critical. For example, it's not uncommon that I use a CPL, ND and GND at the same time. This generally isn't possible or desirable with the screw-on filter system.

Next steps


Filters are an incredibly important tool for outdoor photographers. It's not something you'll need for each and every shot, but, more often than not, they will have a positive impact on your photography.

It's always difficult to give exact recommendations as your needs depends on what type of photographer you are. Personally, I've been using a square filter system from NiSi for several years, and I have been extremely happy with these. I've tested an abundance of filters in all price ranges, and NiSi remains the brand that I stay loyal to.

I recommend that those of you who have never used filters before the start by purchasing a few more affordable screw-on filters to start practising. More specifically, you should get a CPL and a 3-Stop and 6-Stop ND Filter. These three will do wonders for your photography.

When you've experimented some with filters, I recommend moving over to a square filter system. The 'Beginners Kit' from NiSi is a good place to start.

High-quality filters last for a long time, so you can slowly build your kit to include what you need.